This is a resubmission of an application to support the controlled evaluation of a standardized multicomponent cognitive behavioral treatment program for child and adolescent Obsessive-Compulsive Disorder (OCD). The treatment program consists of individual exposure plus response prevention (ERP) for the OCD child plus a concurrent family intervention designed to reduce OCD-related family conflict, facilitate family disengagement from the affected child's OCD behavior, and rebuild normal family interaction patterns. A total of eighty (80) medication- free youngsters and their families will be randomly assigned to receive either the combined ERP/Family Treatment Program (n=56) or a comparison treatment, Relaxation Training (RT) (n=24). Both treatments will be delivered over 12 90 minute outpatient sessions according to detailed treatment manuals. RT was selected as the comparison treatment because of its credibility as an anxiety treatment and familiarity to potential subjects. RT has been used as a comparison condition for at least two randomized controlled ERP trials for adult OCD and shown to be ineffective in treating this disorder. OCD is a chronic, often disabling disorder in childhood. Preliminary studies suggest that ERP is an effective treatment for children with OCD although no controlled trials to this effect have been published. OCD in childhood has been associated with increased rates of parental psychopathology and significant disruptions in family relationships and functioning. Moreover, family contextual variables have been associated with both a worse treatment response and a poorer long-term outcome. Although it has long been hypothesized that family participation in treatment may be helpful, this is the first controlled study incorporating a systematic manualized family treatment component. Youngsters and families will undergo comprehensive, systematic, including behavioral, assessments by blind clinical evaluators at baseline, monthly during treatment, posttreatment, and two follow-up evaluations over six months. Treatment outcome will be examined in multimodal fashion and across multiple functional domains with a special emphasis on family contextual variables. The impact of baseline functioning, including family context, and initial change over time on treatment outcome will also be systematically evaluated.